Splitted out the GdkPixbuf to NSImage routine so that it can be used from

Splitted out the GdkPixbuf to NSImage routine so that it can be used from

2006-12-19  Mikael Hallendal  <micke@imendio.com>

	* gdk/quartz/gdkcursor-quartz.c: Splitted out the GdkPixbuf to NSImage
	routine so that it can be used from libgtk as well (needed for
	upcoming GtkStatusIcon support in the Quartz port).
	* gdk/quartz/gdkevents-quartz.c: Don't assume that all NSWindows are
	created from GDK, this is not true for the status icon.
	* gdk/quartz/gdkprivate-quartz.h:
	* gdk/quartz/gdkquartz.h: Added
	gdk_quartz_pixbuf_to_ns_image_libgtk_only so that it is available to
	the status icon code.